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Microbiology Spectrum Mar 2019Streptococci carrying serogroup C and G antigens, and in particular, subsp. (SDSE), are emerging human pathogens that are increasingly isolated from patients with a... (Review)
Review
Streptococci carrying serogroup C and G antigens, and in particular, subsp. (SDSE), are emerging human pathogens that are increasingly isolated from patients with a myriad of infections that range from mundane to life-threatening. SDSE is microbiologically similar to . These streptococci frequently cause infections of the throat and skin and soft tissues. Moreover, they may invade the bloodstream and disseminate widely to many deep tissue sites, including the endocardium. Life-threatening invasive infections due to SDSE, including the streptococcal toxic shock syndrome, occur most frequently in patients with severe underlying medical diseases. Treatment with penicillin is adequate under most circumstances, but treatment failure occurs. SDSE may also be resistant to other antibiotic classes including tetracyclines, macrolides, and clindamycin. Most human infections caused by groups C and G streptococci are transmitted from person to person, but infections due to subsp. (and, rarely, to subsp. ) are zoonoses. Transmission of these latter species occurs by animal contact or by contamination of food products and has been associated with the development of poststreptococcal glomerulonephritis. Members of the group, usually classified with the viridans group of streptococci, are associated with a variety of pyogenic infections.
Topics: Animals; Anti-Bacterial Agents; Drug Resistance, Bacterial; Glomerulonephritis; Humans; Pharyngitis; Streptococcal Infections; Streptococcus; Zoonoses
PubMed: 30977463
DOI: 10.1128/microbiolspec.GPP3-0016-2018 -
Journal of Veterinary Internal Medicine Mar 2018This consensus statement update reflects our current published knowledge and opinion about clinical signs, pathogenesis, epidemiology, treatment, complications, and...
This consensus statement update reflects our current published knowledge and opinion about clinical signs, pathogenesis, epidemiology, treatment, complications, and control of strangles. This updated statement emphasizes varying presentations in the context of existing underlying immunity and carrier states of strangles in the transmission of disease. The statement redefines the "gold standard" for detection of possible infection and reviews the new technologies available in polymerase chain reaction diagnosis and serology and their use in outbreak control and prevention. We reiterate the importance of judicious use of antibiotics in horses with strangles. This updated consensus statement reviews current vaccine technology and the importance of linking vaccination with currently advocated disease control and prevention programs to facilitate the eradication of endemic infections while safely maintaining herd immunity. Differentiation between immune responses to primary and repeated exposure of subclinically infected animals and responses induced by vaccination is also addressed.
Topics: Animals; Consensus; Disease Outbreaks; Horse Diseases; Horses; Lymphadenitis; Streptococcal Infections; Streptococcus equi; Vaccination
PubMed: 29424487
DOI: 10.1111/jvim.15043 -
Journal of Comparative Pathology Apr 2020The canine infectious respiratory disease complex (CIRDC) is an endemic worldwide syndrome involving multiple viral and bacterial pathogens. Traditionally, Bordetella... (Review)
Review
The canine infectious respiratory disease complex (CIRDC) is an endemic worldwide syndrome involving multiple viral and bacterial pathogens. Traditionally, Bordetella bronchiseptica (Bb), canine adenovirus type 2 (CAV-2), canine distemper virus (CDV), canine herpesvirus (CHV) and canine parainfluenza virus (CPiV) were considered the major causative agents. Lately, new pathogens have been implicated in the development of CIRDC, namely canine influenza virus (CIV), canine respiratory coronavirus (CRCoV), canine pneumovirus (CnPnV), Mycoplasma cynos and Streptococcus equi subspecies zooepidemicus. To better understand the role of the different pathogens in the development of CIRDC and their epidemiological relevance in Europe, prevalence data were collected from peer-reviewed publications and summarized. Evidence of exposure to Bb is frequently found in healthy and diseased dogs and client-owned dogs are as likely to be infected as kennelled dogs. Co-infections with viral pathogens are common. The findings confirm that Bb is an important cause of CIRDC in Europe. CAV-2 and CDV recovery rates from healthy and diseased dogs are low and the most likely explanation for this is control through vaccination. Seroconversion to CHV can be demonstrated following CIRDC outbreaks and CHV has been detected in the lower respiratory tract of diseased dogs. There is some evidence that CHV is not a primary cause of CIRDC, but opportunistically re-activates at the time of infection and exacerbates the disease. The currently available data suggest that CIV is, at present, neither a prevalent nor a significant pathogen in Europe. CPiV remains an important pathogen in CIRDC and facilitates co-infection with other viral and bacterial pathogens. CnPnV and CRCoV are important new elements in the aetiology of CIRDC and spread particularly well in multi-dog establishments. M. cynos is common in Europe and is more likely to occur in younger and kennelled dogs. This organism is frequently found together with other CIRDC pathogens and is significantly associated with more severe respiratory signs. S. zooepidemicus infection is not common and appears to be a particular problem in kennels. Protective immunity against respiratory diseases is rarely complete, and generally only a reduction in clinical signs and excretion of pathogen can be achieved through vaccination. However, even vaccines that only reduce and do not prevent infection carry epidemiological advantages. They reduce spread, increase herd immunity and decrease usage of antimicrobials. Recommending vaccination of dogs against pathogens of CIRDC will directly provide epidemiological advantages to the population and the individual dog.
Topics: Animals; Dog Diseases; Dogs; Europe; Prevalence; Respiratory Tract Infections
PubMed: 32359641
DOI: 10.1016/j.jcpa.2020.02.005 -
Proceedings of the National Academy of... Jun 2023M family proteins are critical virulence determinants of Streptococci. subsp. (SEZ) are Group C streptococci that cause meningitis in animals and humans. SzM, the M...
M family proteins are critical virulence determinants of Streptococci. subsp. (SEZ) are Group C streptococci that cause meningitis in animals and humans. SzM, the M protein of SEZ, has been linked to SEZ brain invasion. Here, we demonstrate that SzM is important in SEZ disruption of the blood-brain barrier (BBB). SEZ release SzM-bound membrane vesicles (MVs), and endocytosis of these vesicles by human brain endothelial microvascular cells (hBMECs) results in SzM-dependent cytotoxicity. Furthermore, administration of SzM-bound MVs disrupted the murine BBB. A CRISPR screen revealed that SzM cytotoxicity in hBMECs depends on PTEN-related activation of autophagic cell death. Pharmacologic inhibition of PTEN activity prevented SEZ disruption of the murine BBB and delayed mortality. Our data show that MV delivery of SzM to host cells plays a key role in SEZ pathogenicity and suggests that MV delivery of streptococcal M family proteins is likely a common streptococcal virulence mechanism.
Topics: Humans; Animals; Mice; Blood-Brain Barrier; Autophagic Cell Death; Antigens, Bacterial; Streptococcus; Streptococcus equi; Endothelial Cells; Streptococcal Infections
PubMed: 37276410
DOI: 10.1073/pnas.2219435120 -
Molecular Microbiology Mar 2017The collagen domain, which is defined by the presence of the Gly-X-Y triplet repeats, is amongst the most versatile and widespread known structures found in proteins... (Review)
Review
The collagen domain, which is defined by the presence of the Gly-X-Y triplet repeats, is amongst the most versatile and widespread known structures found in proteins from organisms representing all three domains of life. The streptococcal collagen-like (Scl) proteins are widely present in pathogenic streptococci, including Streptococcus pyogenes, S. agalactiae, S. pneumoniae, and S. equi. Experiments and bioinformatic analyses support the hypothesis that all Scl proteins are homotrimeric and cell wall-anchored. These proteins contain the rod-shaped collagenous domain proximal to cell surface, as well as a variety of outermost non-collagenous domains that generally lack predicted functions but can be grouped into one of six clusters based on sequence similarity. The well-characterized Scl1 proteins of S. pyogenes show a dichotomous switch in ligand binding between human tissue and blood environments. In tissue, Scl1 adhesin specifically recognizes the wound microenvironment, promotes adhesion and biofilm formation, decreases bacterial killing by neutrophil extracellular traps, and modulates S. pyogenes virulence. In blood, ligands include components of complement and coagulation-fibrinolytic systems, as well as plasma lipoproteins. In all, the Scl proteins signify a large family of structurally related surface proteins, which contribute to the ability of streptococci to colonize and cause diseases in humans and animals.
Topics: Adhesins, Bacterial; Amino Acid Sequence; Animals; Bacterial Adhesion; Bacterial Proteins; Biofilms; Collagen; Humans; Protein Binding; Protein Domains; Streptococcus agalactiae; Streptococcus pneumoniae; Streptococcus pyogenes; Virulence Factors
PubMed: 27997716
DOI: 10.1111/mmi.13604 -
Clinical Microbiology and Infection :... Jan 2016
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Animals; Child; Child, Preschool; Cohort Studies; Environmental Exposure; Female; Humans; Infant; Male; Meningitis; Middle Aged; Streptococcal Infections; Streptococcus equi; Young Adult
PubMed: 26369601
DOI: 10.1016/j.cmi.2015.09.003 -
Frontiers in Cellular and Infection... 2017subsp. () is an opportunistic pathogen of several species including humans. is found on mucus membranes of healthy horses, but can cause acute and chronic...
subsp. () is an opportunistic pathogen of several species including humans. is found on mucus membranes of healthy horses, but can cause acute and chronic endometritis. Recently was found able to reside in the endometrium for prolonged periods of time. Thus, we hypothesized that an intracellular phase may be part of the pathogenesis and investigated if was able to invade and survive inside epithelial cells. HEp-2 and HeLa cell lines were co-cultured with two strains (1-4a and S31A1) both originating from the uterus of mares suffering from endometritis. Cells were fixed at different time points during the 23 h infection assay and field emission scanning electron microscopy (FESEM) was used to characterize adhesion and invasion mechanisms. The FESEM images showed three morphologically different types of invasion for both bacterial strains. The main port of entry was through large invaginations in the epithelial cell membrane. Pili-like bacterial appendages were observed when the cells were in close proximity to the epithelial cells indicating that attachment and invasion were active processes. Adherent and intracellular , and bacteria in association with lysosomes was determined by immunofluorescence staining techniques and fluorescence microscopy. Quantification of intracellular bacteria was determined in penicillin protection assays. Both strains investigated were able to invade epithelial cells although at different magnitudes. The immunofluorescence data showed significantly higher adhesion and invasion rates for strain 1-4a when compared to strain S31A1. was able to survive intracellularly, but the survival rate decreased over time in the cell culture system. Phagosome-like compartments containing at some stages fused with lysosomes to form a phagolysosome. The results indicate that an intracellular phase may be one way survives in the host, and could in part explain how can cause recurrent/persistent infections. Future studies should reveal the ability of to internalize and survive in primary equine endometrial cells and during conditions.
Topics: Adhesins, Bacterial; Animals; Cell Line; Coculture Techniques; Colony Count, Microbial; Endometritis; Epithelial Cells; Female; HeLa Cells; Hep G2 Cells; Horse Diseases; Horses; Host-Pathogen Interactions; Humans; Lysosomes; Microbial Sensitivity Tests; Microscopy, Electron, Scanning; Streptococcal Infections; Streptococcus
PubMed: 29164073
DOI: 10.3389/fcimb.2017.00465 -
Transboundary and Emerging Diseases Sep 2022In 2019, Streptococcus equi subsp. zooepidemicus was recognized as an emerging pathogen of swine, associated with sudden deaths, increased abortion rates and...
In 2019, Streptococcus equi subsp. zooepidemicus was recognized as an emerging pathogen of swine, associated with sudden deaths, increased abortion rates and septicaemia. Limited data are available regarding this disease in pigs. The objectives of this study were to clarify clinical progression, pathogen shedding, transmission, gross and microscopic lesions following infection in pigs. Six weeks old pigs were inoculated with either S. zooepidemicus sequence type 194 (inoculated, n = 6) or sham inoculated with sterile culture broth (sentinels, n = 4). Animals were housed in the same room, in two pens 2 m apart. Pigs were monitored twice daily for clinical signs, and rectal, nasal and oral swabs were collected once daily. A full necropsy was performed if welfare was a concern or at 5 days post-inoculation (dpi). All sentinels remained disease free and their samples tested negative for the pathogen of interest. All inoculated pigs developed fever within 8 h of inoculation, and severe disease was observed after 2 dpi. A total of 4/6 inoculated pigs developed clinical signs that compromised animal welfare and were euthanized. Nasal swabs (15/23), followed by rectal swabs (9/23) yield the highest number of positive ante-mortem samples. Clinically healthy, inoculated pigs had detectable levels of S. zooepidemicus in rectal and nasal swabs. Reactive submandibular lymph nodes, kidney petechiae and splenomegaly were found in six of six inoculated pigs. These data suggest that subclinically infected pigs may spread the pathogen through nasal secretions and faeces. Direct contact seems to be required for transmission.
Topics: Animals; Carrier State; Feces; Streptococcus equi; Swine
PubMed: 35182443
DOI: 10.1111/tbed.14481 -
IDCases 2020subsp. is a group C β-hemolytic streptococcus, and is an invasive pathogen with a very restricted host, causing the equine infection known as 'strangles'. It is a...
subsp. is a group C β-hemolytic streptococcus, and is an invasive pathogen with a very restricted host, causing the equine infection known as 'strangles'. It is a poor colonizer in horses, preferentially causing invasion and infection, compared with its ancestor subsp. , which is considered an opportunistic commensal of the equine upper respiratory tract. In humans, subsp. causes invasive infections in immunocompromised hosts, often following close contact with horses. Such infections are associated with a high mortality, as well as a poor neurological outcome in survivors. Beta-lactam antimicrobials form the mainstay of treatment, while neurosurgical intervention is occasionally required. We present the case of a 13-year old boy with systemic lupus erythematosus being treated with hydroxychloroquine, who presented with subsp. meningitis and sepsis after contact with a sick pony. Although he recovered fully following eight weeks of intravenous ceftriaxone and oral rifampin, the clinical course was complicated by subdural empyema requiring neurosurgical evacuation.
PubMed: 32489871
DOI: 10.1016/j.idcr.2020.e00808 -
Journal of Veterinary Internal Medicine Jan 2019Streptococcus equi subspecies equi infection elicits M protein antibody titers in equids. Interpretation of titers is not generally accepted.
BACKGROUND
Streptococcus equi subspecies equi infection elicits M protein antibody titers in equids. Interpretation of titers is not generally accepted.
HYPOTHESIS
The magnitude of S. equi M protein (SeM) antibody titer after infection (titer ≥1:12 800) will be useful to monitor for the presence of complications or the risk of development of complications.
ANIMALS
Forty-eight horses on 1 farm involved in strangles outbreak.
METHODS
Clinical and observational study. S. equi M protein antibody titers were measured on all horses 8 weeks after infection and select horses 12 and 28 weeks after infection. Horses were categorized: no disease, uncomplicated case, persistent guttural pouch (GP) infection, or complicated cases (metastatic abscesses, purpura hemorrhagica, secondary infections, and dysphagia). Category was compared to titer.
RESULTS
Twenty-eight of 48 (58%) developed clinical signs of S. equi infection. Of those, 11 (39%) had uncomplicated strangles, 9 (21%) had persistent GP infection, 5 (18%) were complicated cases, and 3 (11%) had both persistent GP infection and complications. Thirty-three percent of horses (16 of 48) had SeM antibody titers ≥1:12 800 eight weeks after infection. Of horses with titers ≥1:12 800, 6 of 16 had evidence of complications. Of complicated cases, 6 of 8 had titers ≥1:12 800. In this outbreak, the sensitivity (75%; 95% CI [confidence interval] 45-105) for a SeM antibody titer ≥1:12 800 detecting complications was higher than the specificity (43%; 95% CI 23-64).
CONCLUSIONS AND CLINICAL IMPORTANCE
This outbreak demonstrates that SeM antibody titers can be increased after infection (≥1:12 800) in the absence of complications of strangles.
Topics: Animals; Antibodies, Bacterial; Female; Horse Diseases; Horses; Male; Risk Factors; Streptococcal Infections; Streptococcus equi
PubMed: 30520521
DOI: 10.1111/jvim.15388